Simultaneous control of the wavelength and duration of Raman-shifting solitons using topographic photonic crystal fibers

We report an original way to control simultaneously the wavelength and duration of ultrashort solitons by using topographic photonic crystal fibers. The design of these longitudinally modulated fibers is achieved by using an accurate and simple approach based on analytical and semi-analytical tools, avoiding the use of time-consuming numerical simulations. Starting from realistic initial conditions, we show that the central wavelength of the soliton at the fiber output can be adjusted over more than 200 nm with a duration ranging from 80 to 280 fs, respectively. Experimental demonstrations, performed in five different fibers, are in excellent agreement with theoretical predictions, thus validating our approach. This new family of tunable fiber sources can be of great interest for nonlinear microscopy applications. (C) 2015 Optical Society of America